The present invention falls within the field of construction of electronic apparatuses such as hand held calculators, electronic learning aids and hand held electronic games. Construction of apparatuses of this type was disclosed in U.S. Pat. No. 3,819,921 "Miniature Electronic Calculator" issued to Jack S. Kilby, Jerry D. Merryman and James H. Van Tassel on June 25, 1974. This patent discloses a hand held calculator including a keyboard input means, a visual display device and an integrated semiconductor circuit array located in substantially one plane including memory for storing entered digits, an arithmetic unit for performing calculations and a control unit controlling the transfer of data from the memory to the arithmetic unit and back to the memory.
Since the innovation described in U.S. Pat. No. 3,819,921 major improvements in the computational ability and reductions in the cost of such apparatuses have been achieved. Heretofore such advances in the art of manufacture of miniature electronic apparatuses have come about due to improvements in the semiconductor art, specifically improvements in the complexity and reductions in the cost of integrated circuit semiconductor devices which form the primary electrical component of such apparatuses. Such innovations are exemplified by U.S. Pat. No. 4,074,351 "Variable Function Programmed Calculator" issued to Gary W. Boone and Michael H. Cochran on Feb. 14, 1978, which discloses an improved integrated circuit such as employed in apparatuses of this type. U.S. Pat. No. 4,326,265 "Variable Function Programmed Calculator" issued to Gary W. Boone on Apr. 20, 1982 discloses an electronic system which advantageously employs the integrated circuit taught in U.S. Pat. No. 4,074,351.
The improvements in the semiconductor integrated circuit exemplified by the above cited patents have resulted in revolutionary improvements in apparatuses of this type. However, further improvements in semiconductor electronic technology presently yield decreasing benefits in the complexity and cost of such apparatuses, particularly in the field of low cost apparatuses. As a result, further decreases in cost will now become more dependent upon improvements in the manufacturability of these apparatuses. This is because improvements in integrated circuit technology have proceeded at such a rapid pace that this area of the apparatus assumes a decreasing proportion of the total cost of manufacture. Thus improvements in the manufacturability of such apparatuses assume a corresponding increasing importance in the total cost of such an electronic apparatus.